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United States Patent | 5,322,724 |
Levens | June 21, 1994 |
A laminate formed by heat fusing a heat sealable polyolefin sheet to two cured polyolefin sheets to produce a water impermeable seal between the cured polyolefin sheets. The heat sealable polyolefin sheet is preferably bonded to a porous heat resistant backing on one surface and the other surface is heat fused to the cured polyolefin sheets. The cured polyolefin sheets may typically be in juxtaposed or overlapping arrangement. The porous backing may be in the form of a fibrous sheet. The heat sealable polyolefin sheet is preferably low density polyethylene and the cured polyolefin sheets are typically cured EPDM rubber.
Inventors: | Levens; Dennis L. (Hudson, WI) |
Assignee: | Minnesota Mining and Manufacturing Company (St. Paul, MN) |
Appl. No.: | 810208 |
Filed: | December 19, 1991 |
Current U.S. Class: | 428/57; 428/58; 428/141; 428/147; 428/213; 428/220; 428/332; 428/337; 428/339; 428/349; 428/354; 428/492; 428/493; 428/495; 428/521; 442/290; 442/293; 442/398; 442/399; 524/495; 524/496 |
Intern'l Class: | B32B 003/06; C09J 005/02; 517; 519; 213; 220; 332; 337; 339; 343; 347; 349; 354 |
Field of Search: | 428/57,58,141,492,493,521,495,61,264,267,268,265,260,286,287,290,147,507,516 52/408,409 524/495,496 |
2450083 | Sep., 1948 | Donaldson | 428/40. |
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3650874 | Mar., 1972 | Job et al. | 161/217. |
3904470 | Sep., 1975 | Fukuki et al. | 156/306. |
4410575 | Oct., 1983 | Obayashi | 428/57. |
4421807 | Dec., 1983 | Clausing et al. | 428/41. |
4480012 | Oct., 1984 | Fieldhouse | 428/306. |
4501842 | Feb., 1985 | Chmiel et al. | 524/432. |
4514442 | Apr., 1985 | Crepeau | 427/140. |
4537825 | Aug., 1985 | Yardley | 428/327. |
4563379 | Jan., 1986 | Kruger | 428/61. |
4581092 | Apr., 1986 | Westley | 156/306. |
4588637 | May., 1986 | Chiu | 428/355. |
4640730 | Feb., 1987 | Streets et al. | 156/334. |
4720039 | Jan., 1988 | Nishiguchi | 428/57. |
4732635 | Mar., 1988 | Levens | 156/230. |
4740413 | Apr., 1988 | Wildner | 428/198. |
4743332 | May., 1988 | Black | 156/359. |
4767653 | Aug., 1988 | Renstrom | 428/40. |
4767658 | Aug., 1988 | Lorenz | 428/192. |
4800120 | Jan., 1989 | Jadamus | 428/286. |
4913772 | Apr., 1990 | Taylor et al. | 156/499. |
5093171 | Mar., 1992 | Sheahan | 428/61. |
5093206 | Mar., 1992 | Schoenbeck | 428/521. |
5096743 | Mar., 1992 | Schoenbeck | 427/189. |
Foreign Patent Documents | |||
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